1. The evolving concept of life is based on emerging pieces of evidence discovered over centuries. During the 1800s, geologists found fossils of ancient sea life on dry land and layers of rock, supporting the idea that Earth and life changed over time. 2. Various pieces of evidence have helped trace the history of life on Earth, including fossils, rock layers, and indications of past volcanic activity and erosion. Understanding the history of life allows prediction of future changes and helps address challenges like pandemics. 3. Key evidence includes ancient bacteria and stromatolites, showing life first emerged as prokaryotic and anaerobic organisms over 3.5 billion years ago, and evolved with environmental changes like the oxygen

1. CO_Q2_ELS SHS
Module 1
Earth and Life Science
Quarter 2 – Module 1:
Evolving Concept of Life Based
on Emerging Pieces of Evidence

2. Earth and Life Science
Alternative Delivery Mode
Quarter 2 – Module 1: Evolving Concept of Life Based on Emerging Pieces of
Evidence
First Edition, 2021
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Development Team of the Module
Writers: Vivan A. Novales, Rhodora G. Bautista
Editors: Melanie I. Samudio, Jocelyn M. Manset
Reviewers: Jason Ricaforte, Elizabeth A. Soriano, Princess Paolah L. De Guzman,
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Mario B. Maramot
Fe M. Ong-ongowan
Rosalinda A. Mendoza

3. Earth and Life Science
Quarter 2 – Module 1:
Evolving Concept of Life Based
on Emerging Pieces of Evidence

4. Introductory Message
This Self-Learning Module (SLM) is prepared so that you, our dear learners,
can continue your studies and learn while at home. Activities, questions, directions,
exercises, and discussions are carefully stated for you to understand each lesson.
Each SLM is composed of different parts. Each part shall guide you step-by-
step as you discover and understand the lesson prepared for you.
Pre-tests are provided to measure your prior knowledge on lessons in each
SLM. This will tell you if you need to proceed on completing this module or if you
need to ask your facilitator or your teacher’s assistance for better understanding of
the lesson. At the end of each module, you need to answer the post-test to self-check
your learning. Answer keys are provided for each activity and test. We trust that you
will be honest in using these.
In addition to the material in the main text, Notes to the Teacher are also
provided to our facilitators and parents for strategies and reminders on how they can
best help you on your home-based learning.
Please use this module with care. Do not put unnecessary marks on any part
of this SLM. Use a separate sheet of paper in answering the exercises and tests. And
read the instructions carefully before performing each task.
If you have any questions in using this SLM or any difficulty in answering the
tasks in this module, do not hesitate to consult your teacher or facilitator.
Thank you.

5. 1 CO_Q2_ELS SHS
Module 1
What I Need to Know
This module was designed and written with you in mind. It is here to help you master
the nature of Biology. The scope of this module permits it to be used in many different
learning situations. The language used recognizes the diverse vocabulary level of
students. The lessons are arranged to follow the standard sequence of the course.
But the order in which you read them can be changed to correspond with the
textbook you are now using.
The module covers:
• Lesson 1 – Historical Development of the Concepts of Life
Learning Competency: Explain the evolving concept of life based on emerging
pieces of evidence. (S11/12LT-IIa-1)
After going through this module, you are expected to:
1. identify the sequence of events of the history of life on earth;
2. name the pieces of evidence on the evolution of life on earth; and
3. recognize the importance of knowing the history of life on earth.

6. 2 CO_Q2_ELS SHS
Module 1
What I Know
Directions: Choose the letter of the best answer. Write the chosen letter on a
separate sheet of paper.
1. Dinosaurs are reptiles that existed for a very long time. Which era did these
organisms evolve?
a. Cenozoic Era
b. Mesozoic Era
c. Paleozoic Era
d. Proterozoic Era
2. What are the first photosynthetic organisms that grew well on earth?
a. bryophyllum
b. cyanobacteria
c. stromatolites
d. zircon crystal
3. The oxygen revolution changed Earth’s environment dramatically. Which of
the following adaptations took advantage of the presence of free oxygen in
the oceans and atmosphere?
a. The evolution of cellular respiration, which used oxygen to help
harvest energy from organic molecules.
b. The evolution of chloroplasts after early protists incorporated
photosynthetic cyanobacteria
c. The evolution of multicellular eukaryotic colonies from communities
of prokaryotes.
d. The evolution of photosynthetic pigments that protected early algae
from the corrosive effects of oxygen.
4. Why did it take millions of years for life to appear on Earth after the planet
had formed?
a. It took millions of years for RNA to replace DNA.
b. The planet had warmed up enough to sustain life.
c. The planet had cooled down enough to sustain life.
d. Life on Earth could begin only when seedlings arrived on our planet
from other worlds.
5. Which types of organisms developed first due to the early environmental
conditions on Earth?
a. eukaryotic and aerobic
b. eukaryotic and anaerobic
c. prokaryotic and aerobic
d. prokaryotic and anaerobic

7. 3 CO_Q2_ELS SHS
Module 1
6. What are called the remains of living organism used in understanding the
history of life on earth?
a. bone
b. fossils
c. seeds
d. shells
7. Which statement is NOT true of fossils?
a. Plants can form fossils.
b. Some bacteria can form fossils.
c. Most extinct organisms have been preserved.
d. A small percent of extinct organisms is preserved.
8. Which of the following can be considered as a fossil?
a. a billion-year old rock
b. a billion-year old piece of amber
c. a billion-year old amber with a primitive insect inside
d. the choices are all correct
9. What unique substance do researchers look after in their study of
eukaryotes?
a. biomarkers
b. fossils
c. mitochondria
d. stromatolites
10. What is the evidence for a last universal common ancestor among life on
earth?
a. They are all aerobic.
b. They all look the same.
c. They all have the same synthesis pattern.
d. They share the same underlying molecular biology.
11. Which statement best shows the main significance of studying the past?
a. The past is attractive to look back.
b. It will give jobs for many scientists and paleontologists.
c. It will allow them to think what they need to study.
d. Understanding the past allows us to predict the future and help in
creating it.
12. One significance of knowing the history of life is to determine the origin of
one living organism. According to researchers, which of the following are the
only surviving species of the genus Homo and one of the living evidences
that life has existed on Earth?
a. birds
b. dinosaurs
c. human beings
d. sponges

8. 4 CO_Q2_ELS SHS
Module 1
13. Over the past decades, there are challenges that the environment has faced.
Pandemics affected the lives of various living organisms. What is the
significance of knowing this history?
a. It will give them an income.
b. They will just be informed about it.
c. It will lead them to know the history of life.
d. It will give an idea on how medical world will seek for the treatment.
14. The following statements are challenges for the researchers in
finding and identifying signs of early cells. Which is not part of the
group?
a. Materials and testing laboratories are not available.
b. Cells are microscopic and most have no parts to fossilize
c. Slightly younger rocks have been heated up and undergone other
processes
d. Tectonic plate movements have destroyed nearly all rocks older than
about 4 billion years
15. The study of history of life is significant in many aspects. The
stromatolites played a significant role as a source of evidence. What
is stromatolite?
a. It is found in animals.
b. It is produced by endosymbiosis.
c. It formed during volcanic eruptions.
d. It consists of layered bacteria and sediment.

9. 5 CO_Q2_ELS SHS
Module 1
Lesson
1
Evolving Concept of Life
Based on Emerging Pieces of
Evidence
Have you been curious of when and where did life possibly start on Earth? During
the 1800s, geologists and the naturalists found several forms of physical evidence
that confirmed that Earth is very old. The evidence includes: fossils of ancient sea
life on dry land far from oceans, this supported the idea that the Earth changed over
time and some dry land today was once covered by oceans; the many layers of rock
allowed the people to realize that rock layers represent the order in which rocks and
fossils appeared, thus they were able to trace the history of Earth and life on Earth;
lastly, the indications that volcanic eruptions, earthquakes and erosion that
happened long ago shaped much of the Earth’s surface and supported the idea of an
older Earth. This module will help you understand the historical development of the
concept of life based on emerging pieces of evidence. This will trace back the events,
processes, and living organisms existed on earth from the earliest time to present.
What’s In
Activity 1: My Life in Timeline
Directions: Picture out a history of your life. Create a timeline that will reflect the
events that happened to you in the past.
My Life in Timeline

10. 6 CO_Q2_ELS SHS
Module 1
Guide Questions:
1. What is a timeline?
________________________________________________________________________
________________________________________________________________________
2. Why is creating a timeline significant?
________________________________________________________________________
________________________________________________________________________
Notes to the Teacher
This module will help you understand the concepts about historical
development of life. Guide the students by elaborating the simple
and complex concepts included on each activity presented.
Expectedly you will meet the target at the end of the module.

11. 7 CO_Q2_ELS SHS
Module 1
What’s New
Activity 2: Timeline of Events
Directions: Read and analyze the timeline. Arrange the images below the
timeline to show the order of the appearance of life forms on earth.
4.6 – 3.8 BYA
3.5 BYA
3.0 BYA • The first photosynthetic organism
thrived the earth which is blue green
algae called cyanobacteria.
Timeline of
Appearance of
Life Forms
• Life on Earth initially began with
prokaryotes, discovered in sedimentary
rock formations called stromatolites.
500 MYA
250 TYA
• The early earth is said to be violent because
of the meteorites and volcanic eruptions.
With this condition, zircon crystal was
formed.
2.0 BYA • Appearance of the first eukaryotes
and the influx of multicellular
organisms occurred 1.2 billion
years ago.
• The Paleozoic era when the trilobites
and cephalopods became dominant
in the ocean particularly during the
Cambrian and Ordovician.
251 - 65.5 MYA • The Mesozoic era-the age of reptiles that
has a span of 251 to 65.5 MYA divided
into Triassic, Jurassic, and Cretaceous
period.
• The Cenozoic era- recent life and based on
paleontological evidence. Homo erectus have
evolved.

12. 8 CO_Q2_ELS SHS
Module 1
_____________________ _____________________
Green algae
_____________________ _____________________
_____________________
Cephalopod and trilobite
_____________________
Activity 3: Evidence of Life
Directions: Give an evidence on the given events that occurred on geologic time
scale that enables the paleontologist to sequence the history of life.
Hadean
(Early Earth
Development)
Archean
(Period of
Appearance of
first prokaryotes)
Proterozoic Eon
(Period of
appearance of the
first eukaryote)
Paleozoic era
(Dominance of
appearance of
trilobites)
Mesozoic era
(Dominance of
dinosaurs)
Cenozoic era
(Recent Life)

13. 9 CO_Q2_ELS SHS
Module 1
Activity 4: It’s a match!
Directions: Column A are evidences while column B refers to certain timeline. Match
them by writing the letter of your answer on the space before the number.
Column A Column B
_____1. Homo erectus A. 4.3 BYA
_____2. eukaryotes B. 2.0 BYA
_____3. zircon crystal C. Mesozoic Era
_____4. dinosaurs D. 250 thousand years ago
_____5. trilobite fossils E. Cambrian Period
Activity 5: Name It
Directions: Name the pieces of evidence on the evolution of life. Write your answer
on the space provided. Pick your answer from the terms inside the box.
zircon crystal stromatolites cyanobacteria
first eukaryotes multicellular organisms Homo erectus
trilobite fossils first prokaryotes
Period Evidences/Organisms
4.6 to 3.6 billion years ago 1.
3.5 billion years ago 2.
3.0 billion years ago 3.
2.0 billion years ago 4.
1.2 billion years ago 5.
500 million years ago 6.
250 thousand years ago 7.

14. 10 CO_Q2_ELS SHS
Module 1
The universe is about 4.6 billion years old. Life on earth, probably began only
between 3.5 and 4.0 billion years ago. Evidences from fossil records show the
emergence of the different life forms. The common ancestor of all life was prokaryotic.
Since, oxygen was scarce on the early Earth, so the ancestral cell must also have
been an anaerobic. There are some challenges encountered in searching for the
evidence of early life. Cells are microscopic and most have no parts to fossilize. The
tectonic plate movements have destroyed nearly all rocks older than about 4 billion
years, and most of the younger rocks have been heated or undergone processes that
destroy the traces of biological material. At present, the oldest cell microfossils
(microscopic fossils) are filaments from 3.5 billion-year-old rocks in Western
Australia. The filaments resemble chains of modern photosynthetic bacteria and the
rocks in which they occur are the remains of ancient stromatolites.
The researchers look for biomarkers specific to eukaryotes. It is a substance that
occurs only or predominantly in cells of a specific type. Eukaryotes are organisms
having true nucleus. The DNA is enclosed within the nucleus whereas DNA of most
prokaryotes lies enclosed in the cell’s cytoplasm. The first eukaryotes were protists.
For life to evolve from simple single-celled organisms to many millions of species of
prokaryotic species to simple eukaryotic species to all the protists, fungi, plants, and
animals, took some time. The first life forms were very basic and this then allowed
for the evolution of more complex life forms. Eukaryotic cells evolved from prokaryotic
cells. The evolution of life is brought about the changes in the environment which
are linked to changes in climate and geology. These Earth’s environmental changes
made the Earth’s environment more suitable for a wider variety of life forms.
What is It

15. 11 CO_Q2_ELS SHS
Module 1
Activity 6: Arrange Me
Directions: From the given statements below, arrange them to show the origin and
evolution of eukaryotes. Number the boxes from 1-8, 1 as the earliest.
____ G. Endomembrane system
and nucleus evolve through
the modification of cell
membranes
____ H. The modern life-modern
organisms related by
descent.
____ D. The presence of organic
compounds on early Earth.
____ F. Aerobic bacteria lived inside
eukaryotic cell, then
descendants of these bacteria
evolved into mitochondria.
____ E. Oxygen-producing
photosynthetic bacterial cell
entered a eukaryotic cell,
bacterial descendants
evolved into chloroplasts
____ C. Fungi, animals, and algae
that give rise to plants-had
evolved in the seas.
____ A. The emergence of first
celled organisms lacking
nucleus in environment
where oxygen was scarce.
____ B. Photosynthesis and
aerobic respiration evolve in
some bacterial lineages.

16. 12 CO_Q2_ELS SHS
Module 1
What’s More
Activity 7: Time to Reveal
Directions: Arrange the jumbled word to reveal the evidence in the history of life on
earth. Write the answer on the space below the grid.
R I O T L T I E B
• A marine animal first evolved at
the beginning of the Cambrian
period, 542 MYA, where they
dominated the ocean.
E E R C T U S M O H O • Extinct species of the genus Homo
from which the modern human has
evolved from.
A K R P O R Y O T S E
• A basic cell type which lacks true
nucleus. Bacteria, blue-green algae,
archaeans and spirochetes are
examples of organisms belonging to
this cell type.
R U O S D N I A S
• These are giant reptiles that
roamed the earth during the
Mesozoic era.
A K R U E Y O T S E • This basic cell type possesses a
true nucleus that contains DNA.
Activity 8: Origin of Life
Directions: Create a concept map that will discuss how life originated and evolved
based on emerging pieces of evidence using the concepts inside the box.
• history of life ● adaptation
• eukaryotic cell ● photosynthesis
• prokaryotic cell ● scarcity of oxygen
• stromatolites ● biomarkers
• fossils ● organic monomers
• Variation Among Organisms
• Molecular DNA

17. 13 CO_Q2_ELS SHS
Module 1
Activity 9: TMG (Transformations, Mass Extinctions and Geologic Changes)
Directions: Earth’s history is marked by a series of transformations, mass
extinctions and geologic changes that have taken place over the course of 4.6 billion
years. Place the given events on the corresponding time it occurred.
• First evidence of life (3,850 MYA) • Modern humans (0.1 MYA)
• Oldest fossils (3. 500 MYA) • Formation of great oceans (4,200 MYA)
• First evidence of soft bodied animals
(900 MYA)
• Continents begin shifting (3100 MYA)
• The Cambrian Explosion (530 MYA)
• Rodinia supercontinents breaks up
(700 MYA)
• First land plants and fish (480 MYA)
• Pangea supercontinent breaks up (200
MYA)
• First reptiles (350 MYA) • Inland seas dry up (200 MYA)
• First Mammals and dinosaurs (220
MYA)
• Global ice ages begin (2 MYA)
• First birds (150 MYA) • First hominids (5.2 MYA)
• About 50%of marine invertebrate
genera (Late Triassic 206 MYA)
• 25 % of Marine invertebrate families
(End Ordovician 443 MYA)
• Dinosaurs and 60 to 80 percent of all
species (End Cretaceous 65 MYA)
• Many wood land, plant-eating
herbivores (Miocene 9 MYA)
Activity 10: Extinct Flora & Fauna
Directions: The study of the history of life revealed that there were living organisms
that became extinct brought by environmental conditions. In recent times, there are
news on various species that underwent this process. Enumerate flora and fauna
that become extinct and the reasons for this inexistence.
Transformation Mass Extinctions Geologic Changes

18. 14 CO_Q2_ELS SHS
Module 1
Activity 11: Sequence of Events
Directions: Below are some key events happened in the past. Create a timeline that
will show the sequence of events of the history of life. Use the information below as
your guide. You may just use the keywords as part of your timeline.
•The genus Homo gave rise to modern humans, Homo sapiens, us. It is estimated
that they have been around for 2.3-2.4 million years, coinciding with the first
evidence of stone tool usage.
•The first mammals are our most direct ancestors, evolved from Amniotes. One
of the earliest known mammals was Eozostrodon lived about 210 million years
ago.
•Studies of fossils from the Devonian Period 416-359 MYA indicates that land
plants had evolved features we recognized today, such as leaves, roots and
secondary wood.
•Simple eukaryotes, but more advanced organisms, thought to developed 1.6 –
2.1 billion years ago
•Oldest known fossilized prokaryotes have been dated approximately 3.5 billion
years ago
•Around 1.1 billion years ago multicellular organisms are thought to have started
to develop.
•Animals in the most basic sense of the word, have evolved from eukaryotes.
Fossils of early sponges have been discovered in 665 million years old rock.
•560 million years ago, some highly significant fossils of an organism which was
named Charnia were discovered. These enigmatic early animals were anchored
to the sea floor where they are thought to have absorbed nutrients.
Activity 12: Why Should I Study History of Life?
Directions: Write at least fifty-word reflection paper on: “Why should I study history
of life?”.

19. 15 CO_Q2_ELS SHS
Module 1
What I Have Learned
Activity 13: Complete me
Directions: Complete the paragraph by filling-up the blanks with the correct word
from the box.
stromatolites
human Beings
4.6 billion years ago
Cenozoic
Earth
ocean
zircon crystal
Mesozoic Era
3.0 billion years ago
Homo erectus
About (1) __________, the earth was formed as the solar system came into
existence with the other planets rotating around the sun. (2) __________ is said to be
geologically violent because of the continuous bombardment by meteorites and
volcanic eruptions. With this condition, minerals were formed from the elements and
compounds contained in the molten material. The oldest material found on earth is
the (3) __________ that is estimated to be 4.3 billion years old. Life on earth is believed
to begin 3.5 billion years ago with single–celled prokaryotes, as discovered in
sedimentary rock formations called (4) __________. As early as (5) __________, the first
photosynthetic organism thrived the earth which is blue green algae called
cyanobacteria. It was 2.0 billion years ago when the first eukaryotes appeared and
the influx of multicellular organisms occurred 1.2 billion years ago. During the
Paleozoic Era which lasted 542 to 251 MYA, the Cambrian and Ordovician Period
has been known as the age of invertebrates when trilobites and cephalopods became
dominant in the (6) __________. The (7) __________ is the age of reptiles that has a
span of 251 to 65.5 MYA divided into Triassic, Jurassic, and Cretaneous Period. (8)
__________ is the era of recent life and based on paleontological evidence (9) __________
have evolved 250 thousand years ago. (10) __________ are the only surviving species
and one of the living evidences that life have existed on earth.

20. 16 CO_Q2_ELS SHS
Module 1
Directions: You may pick one of the questions to answer in this area. Limit your
answer to 250 words.
1. If the multicellular organisms arise from the unicellular organisms, can you
tell that all the species/organisms are related with one another?
2. If you are one of the environmentalists and was assigned in one of the forests
in the Philippines which happened to be the location of some endangered
species, what are the plans that you would organize to ensure the
conservation of the species of the flora and fauna present in your assigned
area?
3. Write a short poem that will discuss the importance of knowing the concepts
of the history of life to human beings and other living organisms.
What I Can Do

21. 17 CO_Q2_ELS SHS
Module 1
Assessment
Directions: Choose the letter of the best answer. Write the chosen letter on a
separate sheet of paper.
1. Oxygen was scarce during the early development of Earth. By this situation,
what kind of organism first existed?
a. aerobic organism
b. anaerobic organism
c. mammal
d. protist
2. Which of the following statements is NOT true on the evolution of multicellular
organisms?
a. The process of continuous specialization brought more complex
organisms.
b. The prokaryotic organisms that formed multicellular aggregates were
like the cells of Cyanobacteria.
c. They are believed to have evolved from single-celled prokaryotic
organisms.
d. They are formed from other multicellular colonial aggregates through
cells specialization.
3. Why do you think the emergence of plants and animals came later than simple
living organisms?
a. Their existence is not that important on Earth.
b. Their size is too big that it takes longer time for development.
c. The cell structures of these multicellular organisms are more complex.
d. These organisms are composed of many nucleus compared to
unicellular.
4. Which statement is incorrect about living organisms?
a. The earliest forms of life existed were the prokaryotes.
b. The eukaryotic organisms evolved from the unicellular prokaryotic.
c. Organisms did not change despite of the changes in the environment.
d. Evolution of oxygen-producing organisms allowed the increase in the
atmospheric oxygen.
5. Which of the following are in the correct order?
a. eukaryotic cell, photosynthesis, prokaryotic cell, organic molecules
b. eukaryotic cell, prokaryotic cell, organic molecules, photosynthesis
c. organic molecules, eukaryotic cell, photosynthesis, prokaryotic cell
d. organic molecules, prokaryotic cell, photosynthesis, eukaryotic cell

22. 18 CO_Q2_ELS SHS
Module 1
6. What is the evidence for a last universal common ancestor among life on
Earth?
a. All look the same.
b. They have similar synthesis pattern.
c. All are classified as aerobic organisms.
d. They share similar molecular features.
7. What unique substance do researchers look after in their study of eukaryotes?
a. biomarkers
b. fossils
c. mitochondria
d. stromatolites
8. Which of the following can be considered as a fossil?
a. a billion-year old rock
b. a billion-year old piece of amber
c. a billion-year old amber with a primitive insect inside
d. all of the choices are correct
9. Mainly the fossils are found on sedimentary rocks. What type of rocks are
stromatolites?
a. igneous
b. metamorphic
c. sedimentary
d. trilobites
10.Which of the following is NOT true about the evidence that fossils provide?
a. All fossils gathered contain intact DNA that can be sequenced.
b. Fossil ages can often be determined by testing nearby rocks.
c. Fossil organisms often share physical similarities with living
organisms.
d. Some fossil organisms are transitional forms between groups of
organisms.
11.It was stated that the organisms are evolving. The evolution can be due to
environmental changes. More so, the conservation of their traits depends
mainly on how they will survive. In this regard, humans alter the natural world
bringing harmful consequences from their activity. Which among the following
refers to the alteration brought by humans to the natural environment?
a. environmental issues
b. ecosystem conflict
c. environmental topics
d. human intervention

23. 19 CO_Q2_ELS SHS
Module 1
12.What is the significance of studying the molecular evidence present among
living organisms?
a. It will benefit the economy of the world.
b. It will give idea for the scientist which to clone.
c. It will then serve as the basis of what to study.
d. It will allow the classification of living organisms.
13.Over the past several decades, natural selection has caused populations of
Staphylococcus aureus to evolve resistance to most antibiotics. What do you
think would be the significance of being knowledgeable about the history of
this organism towards antibiotics?
a. It will just give them background about the microorganism.
b. It will just give them idea of increasing the frequency of the organisms.
c. It will give an idea of continuing the use of antibiotic against
Staphylococcus aureus.
d. It will give an idea for the medical team to discontinue the use of
particular antibiotic resistant to that microorganism.
14. The study of history of life is indeed significant. As part of searching for the
fossils of previous organisms, stromatolite played a significant role. What is
true about stromatolite?
a. It is found on eukaryotes.
b. It is produced by endosymbiosis.
c. It is formed during volcanic eruptions.
d. It consists of layered bacteria and sediment.
15. The following statements are challenges for the researchers in finding and
identifying signs of early cells. Which is NOT part of the group?
a. Cells are microscopic and most have no parts to fossilize
b. Materials and testing laboratories are not available.
c. Slightly younger rocks have been heated up and undergone other
processes
d. Tectonic plate movements have destroyed nearly all rocks older than
about 4 billion years.
Additional Activities
1. It was stated that researchers faced challenges looking for fossils of the
earliest-life forms. These fossils served as evidence of the origin of life. Based
on your knowledge of tectonic plates, why few samples of early rocks remain?
2. Create an interactive infographic that will show the history of earth.

24. 20 CO_Q2_ELS SHS
Module 1
Answer Key
Activity
10:
Extinct
Flora
&
Fauna
Students’
answer
may
vary
Activity
11:
Sequence
of
Events
1.
Prokaryotes-3.5
billion
2.
Simple
eukaryotes-
1.6-
2.1
BY
3.
Animals-sponges
–
665
MY
4.
Charnia-
560
MY
5.
Land
plants-
416-359
MY
6.
First
mammals-
Eozostrodon-
210
MY
7.
Homo
sapiens-
2.3-2.4
MY
Activity
12:
Why
Should
I
study
History
of
Life
Students’
answer
may
vary
What
I
Have
Learned
Activity
13:
Complete
Me
1.
4.6
billion
years
ago
2.
Earth
3.
zircon
crystal
4.
stromatolites
5.
3.0
billion
years
ago
6.
ocean
7.
Mesozoic
era
8.
Cenozoic
9.
Homo
erectus
10.
human
beings
What
I
Can
Do
Students’
answer
may
vary
Assessment
1.
B
11.
D
2.
D
12.
D
3.
C
13.
D
4.
C
14.
D
5.
D
15.
D
6.
D
7.
A
8.
D
9.
C
10.
A
What
is
It
Activity
6:
Arrange
Me
A.
2
F.
5
B.
3
G.
4
C.
7
H.
8
D.
1
E.
6
What’s
More
Activity
7:
Time
to
Reveal
1.
trilobite
2.
Homo
erectus
3.
prokaryotes
4.
dinosaurs
5.
eukaryotes
Activity
8:
Origin
of
Life
Students’
answer
may
vary
Activity
9:
TMG
Transformations
1.
First
evidence
of
life
2.
Oldest
fossils
3.
First
evidence
of
soft
bodied
animals
4.
The
Cambrian
Explosion
5.
First
land
plants
and
fish
6.
First
mammals
and
dinosaurs
7.
First
birds
8.
First
hominids
9.
Modern
humans
Geologic
Changes
1.
Formation
of
great
oceans
2.
Continents
begin
shifting
3.
Rodinia
supercontinents
breaks
up
4.
Pangea
supercontinents
breaks
up
5.
Inland
seas
dry
up
6.
Global
ice
ages
Mass
Extinctions
1.
50%
invertebrate
genera
2.
Dinosaurs
and
60
to
80
%
of
all
species
3.
25
%
of
marine
invertebrate
families
4.
many
wood
land,
plant-
eating
herbivores
What
I
Know
1.
B
2.
B
3.
A
4.
C
5.
D
6.
B
7.
C
8.
D
9.
A
10.
D
11.
D
12.
C
13.
D
14.
B
15.
D
What’s
In
Activity
1:
My
Life
in
Timeline
Students’
answer
may
vary
What’s
New
Activity
2:
Timeline
of
Events
1.
7
2.
6
3.
3
4.
2
5.
1
6.
4
7.
5
Activity
3:
Evidence
of
Life
1.
zircon
crystal
2.
stromatolites
3.
biomarkers
4.
trilobite
fossils
5.
dinosaur
fossils
7.
Homo
erectus
Activity
4:
It’s
a
Match
1.
D
2.
B
3.
A
4.
C
5.
E
Activity
5:
Name
It
1.
zircon
crystals
2.
stromatolites
3.
cyanobacteria
4.
first
eukaryotic
5.
multicellular
organisms
6.
trilobite
fossil
7.
Homo
erectus

25. 21 CO_Q2_ELS SHS
Module 1
References
A. Books
Ramos, J.D.A. and A.C.M. Ramos. Exploring Life Through Science BIOLOGY.
Quezon City: Phoenix Publishing House, Inc., 2006.
Rea, M.A.D and N.H.A Dagamac. General Biology 2. Manila: Rex Book Store
Inc.,2017.
Robert, Dorothy, Mike, Dana, Donald, David, Cecie, Ralph, Christine, Lisa and
James F. Petersen. Earth and Life Sciences. Manila: Rex Book Store Inc.,
2016
Sia, S.R.D. and L.A.S. Cortez. Earth and Life Science. Quezon City. Sibs Publishing
House, Inc., 2016.
B. Electronic References
David Warmflash & Nathan Lents, “Origins of Life 1: Early Ideas and
Experiments”, accessed June 12, 2020,
https://www.visionlearning.com/en/library/Biology/2/Origins-of-Life-
I/226/quiz
“Deep Time and the History of Life,” PBS Learning Media, accessed June 5,
2020,https://www.pbslearningmedia.org/resource/tdc02.sci.life.div.lp_divd
eeptime/deep-time-and-the-history-of-life/
Jamie Brightmore, “Deep Time: A History of Earth-Interactive Infographic,” Jaybee
Productions, accessed June 3, 2020, https://deeptime.info/Jamie
Brightmore/Jaybee Productions, 2011-2020
“Practice: Fossils: Rocking the Earth quiz,” Khan Academy, accessed June 12,
2020, https://www.khanacademy.org/partner-content/nova/nova-labs-
topic/evolution-101/e/fossils--rocking-the-earth-quiz.

26. For inquiries or feedback, please write or call:
Department of Education - Bureau of Learning Resources (DepEd-BLR)
Ground Floor, Bonifacio Bldg., DepEd Complex
Meralco Avenue, Pasig City, Philippines 1600
Telefax: (632) 8634-1072; 8634-1054; 8631-4985
Email Address: blr.lrqad@deped.gov.ph * blr.lrpd@deped.gov.ph